This invention relates to a rotary kiln with planetary coolers, having a number of cooling tubes disposed in planetary fashion about the periphery of the rotary kiln and each connected with the rotary kiln via an inlet tube attached to the rotary kiln and a transition member acting as an inlet chute to the cooling tube.
In a known rotary kiln with a planetary cooler (German application OLS No. 1,508,518) the cylindrical cooling tubes on the side remote from the rotary kiln are led to the admission point of the inlet tube, and on the side adjacent the rotary kiln are bounded by an inclined cylindrical surface which when the cooling tube is above the kiln axis acts as an inlet chute for the material. The chief disadvantage of this known construction lies in the large height through which the material has to drop on passing from the rotary kiln to the cooling tubes, which results in considerable abrasion and wear of the wall lining. With this construction the air feed is also unsatisfactory, with a sharp deflection, disadvantageous from the flow aspect, of the air between the cooling tubes and the inlet tube.
A rotary kiln with a planetary cooler is also known (German application OLS No. 2,225,097) wherein between the individual cooling tubes and the inlet tubes connected to the rotary kiln there is provided a transition member which on the side remote from the rotary kiln is formed as an inclined inlet chute. With this type of construction the height through which the material drops on passing from the rotary kiln to the cooling tubes is much less than with the device mentioned previously; in addition the air feed conditions are more favourable. However, a disadvantage of this construction is that the connection of the inlet tube to the cooling tube causes dead spaces to occur in the transition zone, which result in deleterious accumulations of material. In addition the transition member between the cooling tubes and the corresponding inlet tubes in this known construction is expensive to construct.